Model 15YN Little Buckaroo

Saw an ad in the local paper for a single shot Marlin Youth rifle for $100. Called the number and he told me it was a model 15. I figured it was a 915, but when I got there to look at it I found that it was in fact a Model 15, and in like NEW condition. I mean spotless. I'd been looking at some 915's for my son, but when I saw this one my search was over. It even came with the original box and manual. Did I do okay?

He said it was about 10 years old, and had shot at the most, maybe 200 rounds. If I read the serial number correctly, it's a 1993 model. First two digits are 07.

So you experts out there, can you tell me when they stopped making the Model 15 in favor of the 915, and what does the "YN" mean (I know the Y is for Youth)? Your input is appreciated.